[DOCS] Assign users to Stack Management cases (#142925)

docs/management/cases/cases.asciidoc

@@ -3,10 +3,10 @@
 
 preview::[]
 
-Cases are used to open and track issues directly in {kib}. All cases list
-the original reporter and all the users who contribute to a case (_participants_).
-You can also send cases to external incident management systems by configuring
-connectors.
+Cases are used to open and track issues directly in {kib}. You can add
+assignees and tags to your cases, set their severity and status, and add alerts,
+comments, and visualizations. You can also send cases to external incident
+management systems by configuring connectors.
 
 [role="screenshot"]
 image::images/cases.png[Cases page]

docs/management/cases/manage-cases.asciidoc

@@ -10,12 +10,15 @@ Open a new case to keep track of issues and share their details with colleagues.
 
 . Go to *Management > {stack-manage-app} > Cases*, then click *Create case*.
 
-. Give the case a name, add any relevant tags and a description.
+. Give the case a name, severity, and description.
 +
 TIP: In the `Description` area, you can use
 https://www.markdownguide.org/cheat-sheet[Markdown] syntax to create formatted
 text.
 
+. Optionally, add assignees and tags. You can add users only if they meet
+the necessary <<setup-cases,prerequisites>>.
+
 . For *External incident management system*, select a connector. For more
 information, refer to <<add-case-connectors>>.
 
@@ -61,10 +64,12 @@ To view a case, click on its name. You can then:
 
 * Add a new comment.
 * Edit existing comments and the description.
+* Add or remove assignees.
 * Add a connector.
 * Send updates to external systems (if external connections are configured).
 * Edit tags.
 * Refresh the case to retrieve the latest updates.
 * Change the status.
+* Change the severity.
 * Close or delete the case.
 * Reopen a closed case.

docs/management/cases/setup-cases.asciidoc

@@ -18,6 +18,12 @@ a|
 NOTE: The *Actions and Connectors* feature privilege is required to create, add,
 delete, and modify case connectors and to send updates to external systems.
 
+| Give assignee access to cases
+a| `All` for the *Cases* feature under *Management*.
+
+NOTE: Before a user can be assigned to a case, they must log into {kib} at
+least once, which creates a user profile.
+
 | Give view-only access for cases | `Read` for the *Cases* feature under *Management*.
 
 | Give access to view and delete cases | `Read` for the *Cases* feature under